1 How did the notion of public dialogue arise? There is a good case to be made that the emphasis on ‘dialogue’ in relation to science and the public in the UK coincided with the publication in 2000 of the House of Lords report on Science and Society. But the impact of that report has to be seen in the context of what was happening under the ‘public understanding of science’ (PUS) banner in the years between the publication of the Bodmer report (1985) and the House of Lords report 15 years later. In the UK, this period
6.1 Control of Substances Hazardous to Health (COSHH) Regulations For those companies involved in the handling of chemicals and/or biological material there are a number of additional regulations. These are known as the Control of Substances Hazardous to Health (COSHH) Regulations. These were introduced in 1988, and the last update was in 1999. These regulations apply to chemicals, biological hazards and dusts. The essential requirements are that the employer must: make an assessment of the health risk to empl
1 History of health and safety The discipline of health and safety is relatively modern, only developing in the last century. However, throughout the ages people have voiced their concerns about people being exposed to harmful substances. Hippocrates mentions in the 4th century BC that lead miners and workers tended to suffer from diseases. The phrase ‘mad as a hatter’ was coined because mercury used in the hat industry caused mental illness. In 1775 Pott reported that chimney s
References 5 Summary At the time of writing (2006) a relatively small number of types of GM crop have been grown globally, in a limited number of countries. The take-up of these crops has been relatively high in countries like the USA and Canada, but very much lower in Europe. However, there is a very rapid increase in the growth of GM crops in developing countries. The technique most commonly used to introduce new genetic material into dicots has involved the use of a modified soil bacterium, Agrobacter 4.1 Vitamin A deficiency Vitamin A, more properly known as retinol, is an important chemical intermediate in a number of biochemical processes in mammals. It is involved in vision, and is found in the rod cells of the retina of the eye. These cells are particularly important in seeing at low light levels, and night blindness is a symptom of vitamin A deficiency (VAD). Vitamin A is also involved in the proper functioning of the immune system. Children suffering from VAD are prone to serious infections, and often die f 3.1 Insect resistance We will now look briefly at the science underlying the traits introduced into commercial crops, which you explored in Activity 1; a useful place to start is by considering how the property of resistance to insects is acquired by crops. Insect damage causes huge losses of agricultural crops each year. For example, without co 2.2 Using A. tumefaciens to genetically modify plant cells Genetic engineers have capitalised on the fact that part of the DNA from the Ti plasmid of A. tumefaciens is integrated into the plant genome during the infection process. Ti plasmids can be isolated and a foreign gene spliced in at an appropriate point, making it possible to transfer the novel gene into the plant. 2.1 Crown gall disease: genetic engineering in nature A. tumefaciens causes crown gall disease in a wide range of dicotyledonous plants. (Dicotyledonous plants, are also known as dicots, have broad leaves with branching veins. An example would be a broad leaved tree like an oak. Narrow leaved plants with parallel grains such as grasses are known as monocotyledonous plant or monocots.) The infection normally occurs at the site of a wound in the plant. The disease gains its name from the large tumour-like swellings, or galls, that o 3.6.2 Experiencing the pregnancy If a woman does find herself pregnant, what can she expect? Pregnancy is a time of enormous physical and emotional changes, and these are often difficult to cope with. To begin with, the physical effects of early pregnancy can be extremely unpleasant. The nausea and vomiting of morning sickness can be very severe, and although in many women the symptoms abate after a while, in others they persist right through the pregnancy. Sickness is thought to be due to the high levels of progestogen circ 3.4.2 Compaction and adhesion Around the time of the 8- to 16-cell division, the conceptus undergoes a morphological (shape) change, called compaction, in which the cells fatten on each other, and the outlines of individual cells become hard to distinguish. This stage, sometimes referred to as a morula, from the Greek word for mulberry, is shown in Figure 17i. At this stage it is hard to see individual cells; in fact, unless the cells are separated by various laboratory treatments, it is not possible to see the two Introduction This unit is from our archive and it is an adapted extract from Human Biology and Health (SK220) which is no longer in presentation. If you wish to study formally at The Open University, you may wish to explore the courses we offer in this curriculum area
. This unit looks at the human being in the context of an individual life cycle, examining some of the processes that 3.4.4 Sediment filling The lifetime of reservoirs can vary greatly. Many reservoirs have lasted for over a hundred years, but some may be useful for only a much shorter period—fifty years or so — not because of the general deterioration of the dam as it gets older, but because sediment accumulates in the reservoir. Rivers carry large amounts of mud, silt and sand in suspension, particularly during floods, and when a river enters a reservoir it slows down and the sediment carried in suspension is deposited on th 4 Groundwater movement Groundwater flows underground in response to elevation differences (downwards) and pressure differences (from areas of high pressure to areas of low pressure). Near the water table, this means that groundwater usually flows ‘downhill’, i.e. from a higher level to a lower level, just as it would on the surface. The difference in energy between two points that are l metres apart horizontally on a sloping water table is determined by the difference in height (h) between them (< Learning outcomes By the end of this unit you should be able to: using information from wells, the topography of the ground and a water table contour map, carry out the following: interpret cross-sections, calculate the thickness of the unsaturated zone, and the rate of groundwater flow; deduce the direction in which groundwater is flowing; and estimate the depth to the saline interface in a coastal area from the height of the water table; list the types of rock that usually make g 3.2 Uranium occurrence and ore deposits In igneous rocks, uranium is more abundant in granites (~3.5 ppm) than in basalts (~1 ppm). The large size of the uranium atom prevents it from easily entering the structures of common rock-forming minerals, so it is an incompatible element that tends to remain in magmas until a late stage of crystallisation, when it enters minor minerals, or even the uranium oxide, uraninite (UO2). In suitable circumstances, following fractional crystallisation of uranium-rich granitic magm 1.3.2 Peat formation in raised mires Mires can also form inland within low-lying depressions, provided the rate of precipitation exceeds the rate of evaporation (Figure 4a). Peat is impermeable and so its accumulation progressively impedes drainage. This attribute gives mires the ability to maintain a water table independent of the area surrounding them. 1.3 Coal-forming environments today Coal formation begins with preservation of waterlogged plant remains to produce peat and then slow compression as the peat is buried. About 10 m of peat will compress down to form about 1 m of coal; clearly large amounts of plant debris must be available for preservation. Even so, for a significant thickness of peat to accumulate there must be a balance between the growth of plants and the decay of underlying dead material to form peat (a process known as humification). Su 1.2 The origins of coal If you examine a piece of coal, at first sight it appears black and rather homogenous. However, closer inspection generally shows a series of parallel bands up to a few millimetres thick. Most obvious are shiny bands that break into angular pieces if struck. Between them are layers of dull, relatively hard coal and thin weak layers of charcoal-like carbon. Coal splits easily along these weak layers, which crumble to give coal its characteristic dusty black coating. Microscopic examinati 1.1 Introduction There are many environmental reasons why coal is a rather undesirable source of energy. Burning it introduces large amounts of gases into the atmosphere that harm the environment in a variety of ways, as well as other, solid waste products. Coal extraction leads to spoil heaps and mines that scar the landscape, land subsidence that affects roads and buildings, and in some cases water pollution. With apparently so little going for it, why do we rely so much on coal to meet our energy nee
